10.6

Table Of Contents
900Logic Pro User Guide
Logic Pro automatically performs surround downmixes and upmixes whenever the format
of the input and output channels don’t match. For example, if you insert a quadraphonic
plug-in into a 5.1 bus, a downmix from 5.1 to Quad, followed by an upmix back to 5.1 occurs
automatically.
Multichannel effects
Logic Pro multichannel effects overview
Effects that are not available as true surround effects can be inserted as multichannel
effects in surround channels. Logic Pro matches the surround format of a channel by
automatically providing the required number of stereo and mono instances of the plug-in.
Multichannel effect plug-ins have an advanced plug-in header.
The plug-in header can include a tab for each effect instance, an LFE tab, and a
Configuration tab. For more information, see Configure multichannel effects in Logic Pro.
The effect tab labels indicate if effect instances are loaded in stereo or mono. Channels
joined with a “-” are loaded as a stereo instance. Channels separated with a “|” are mono.
L-R|Ls-Rs|C: Denotes left/right stereo, left/right surround stereo, mono center.
L-R|Rs|C (a separate left surround tab is shown): Denotes left/right stereo, mono right
surround, mono center.
LR, C, and Ls-Rs shown on three separate tabs: Denotes left/right stereo, center mono,
left/right surround in stereo.
Each effect tab addresses a discrete effect unit for each channel (or channel pair). Each
tab can have different parameter settings.
Click each tab to change plug-in parameters for the LR tab, the C tab, the Ls-Rs tab, and
the LFE tab. The parameter values of each tab are memorized when you save a plug-in
setting.
Side chains and surround effects
When inserting a side chain–capable plug-in, the side chain source (selected in the plug-in
header) is routed to all surround instances.
The detection circuits of grouped plug-in instances are linked, and react as one unit. This
ensures that the spatial surround image is not skewed or deformed.
Note: This is also true when no side chain input is selected. In this case, the group’s
combined individual inputs are used to feed the linked detection circuit—effectively acting
like a side chain source.